<%@ page contentType="image/jpeg" import="java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*"%>
<%!
Color getRandColor(int fc,int bc){
	Random random = new Random();
	if(fc>255) fc=255;
	if(bc>255) bc=255;
	int r=fc+random.nextInt(bc-fc);
	int g=fc+random.nextInt(bc-fc);
	int b=fc+random.nextInt(bc-fc);
	return new Color(r,g,b);
}
%>
<%
response.setHeader("Pragma","No-cache");
response.setHeader("Cache-Control","no-cache");
response.setDateHeader("Expires", 0);

int width=60, height=20;
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

Graphics g = image.getGraphics();

Random random = new Random();

g.setColor(getRandColor(200,250));
g.fillRect(0, 0, width, height);

g.setFont(new Font("Times New Roman",Font.PLAIN,22));


g.setColor(getRandColor(160,200));
for (int i=0;i<155;i++)
{
  int x = random.nextInt(width);
  int y = random.nextInt(height);
  int xl = random.nextInt(12);
  int yl = random.nextInt(12);
  g.drawLine(x,y,x+xl,y+yl);
}

String codeList = "1234567890";

String sRand="";


for (int i=0;i<4;i++){
	int a=random.nextInt(codeList.length()-1);
	String rand=codeList.substring(a,a+1);
	sRand+=rand;
	g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));//调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成
	g.drawString(rand,13*i+6,16);
}

session.setAttribute("sess_code",sRand);

g.dispose();

ImageIO.write(image, "JPEG", response.getOutputStream());
out.clear();
out = pageContext.pushBody();

%>